/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.handler.codec.spdy;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;

abstract class SpdyHeaderBlockDecoder
{

    static SpdyHeaderBlockDecoder newInstance(SpdyVersion spdyVersion,
            int maxHeaderSize)
    {
        return new SpdyHeaderBlockZlibDecoder(spdyVersion, maxHeaderSize);
    }

    /**
     * Decodes a SPDY Header Block, adding the Name/Value pairs to the given
     * Headers frame. If the header block is malformed, the Headers frame will
     * be marked as invalid. A stream error with status code PROTOCOL_ERROR must
     * be issued in response to an invalid frame.
     *
     * @param alloc the {@link ByteBufAllocator} which can be used to allocate
     *        new {@link ByteBuf}s
     * @param headerBlock the HeaderBlock to decode
     * @param frame the Headers frame that receives the Name/Value pairs
     * @throws Exception If the header block is malformed in a way that prevents
     *         any future decoding of any other header blocks, an exception will
     *         be thrown. A session error with status code PROTOCOL_ERROR must
     *         be issued.
     */
    abstract void decode(ByteBufAllocator alloc, ByteBuf headerBlock,
            SpdyHeadersFrame frame) throws Exception;

    abstract void endHeaderBlock(SpdyHeadersFrame frame) throws Exception;

    abstract void end();
}
